Towards a Real-Time, Label-Free, Diamond-Based DNA Sensor
- 16 November 2007
- journal article
- research article
- Published by American Chemical Society (ACS) in Langmuir
- Vol. 23 (26), 13193-13202
- https://doi.org/10.1021/la702143d
Abstract
Most challenging in the development of DNA sensors is the ability to distinguish between fully complementary target ssDNA (single-strand DNA) and 1-mismatch ssDNA. To deal with this problem, we performed impedance spectroscopy on DNA-functionalized nanocrystalline diamond (NCD) layers during hybridization and denaturation. In both reactions, a difference in behavior was observed for 1-mismatch target DNA and complementary target DNA in real-time. During real-time hybridization, a decrease of the impedance was observed at lower frequencies when the complementary target DNA was added, while the addition of 1-mismatch target ssDNA caused no significant change. Fitting these results to an electrical circuit demonstrates that this is correlated with a decrease of the depletion zone in the space charge region of the diamond. During real-time denaturation, differentiation between 1-mismatch and complementary target DNA was possible at higher frequencies. Denaturation of complementary DNA showed the longest exponential decay time of the impedance, while the decay time during 1-mismatch denaturation was the shortest. The real-time hybridization and denaturation experiments were carried out on different NCD samples in various buffer solutions at temperatures between 20 and 80 °C. It was revealed that the best results were obtained using a Microhyb hybridization buffer at 80 °C and 10× PCR buffer at 30 °C for hybridization and 0.1 M NaOH at temperatures above 40 °C for denaturation. We demonstrate that the combination of real-time hybridization spectra and real-time denaturation spectra yield important information on the type of target. This approach may allow a reliable identification of the mismatch sequence, which is the most biologically relevant.Keywords
This publication has 28 references indexed in Scilit:
- Species differentiation by DNA-modified carbon electrodes using an ac impedimetric approachBiosensors and Bioelectronics, 2005
- Sensitive DNA electrical detection based on interdigitated Al/Al2O3 microelectrodesSensors and Actuators B: Chemical, 2004
- Biosensors for clinical diagnostics industrySensors and Actuators B: Chemical, 2003
- Some new aspects in biosensorsReviews in Molecular Biotechnology, 2002
- Growth and characterization of phosphorous doped {111} homoepitaxial diamond thin filmsApplied Physics Letters, 1997
- Quantitative Monitoring of Gene Expression Patterns with a Complementary DNA MicroarrayScience, 1995
- The electrochemical activity of boron-doped polycrystalline diamond thin film electrodesAnalytical Chemistry, 1993
- Detection of base mutations in genomic DNA using denaturing gradient gel electrophoresis (DGGE) followed by transfer and hybridization with gene-specific probesMutation Research, 1988
- Method for detection of specific RNAs in agarose gels by transfer to diazobenzyloxymethyl-paper and hybridization with DNA probes.Proceedings of the National Academy of Sciences of the United States of America, 1977
- Detection of specific sequences among DNA fragments separated by gel electrophoresisJournal of Molecular Biology, 1975